Aging of ceramic materials used in power electronic substrates

In power electronics, the development of new IGBT power modules allows them to switch kV and kA during /spl mu/s. However, such components need to be cooled and ceramic materials like AlN and Al/sub 2/O/sub 3/ are used as an interface between the electronic devices (the chips) and the cooling. Such materials have to present very well known electrical and thermal characteristics since the reliability of the inverters these components are used in is strongly depending on them. In order to increase the knowledge of the physical mechanisms involved during their aging, different experiments are performed (lifetime, breakdown, PD and Space charge measurements...). Electrofracture mechanism is claimed to be responsible of the observed behaviors.